Crusher pitman



G. BUCHANAN CRUSHER PITMAN June 1, .1937.

Filed Feb. 14, 1934 INVEflTO ATTc'aRNEYs Patented June 1, 1937 UNITED STATES PATENT @FFEQE CRUSHER PITMAN Application February 14, 1934, Serial No. 711,177

2 Claims.

This invention relates to crushing apparatus and particularly to a pitman for the toggle or similar mechanism for an oscillatory jaw crusher.

The object of the invention is to provide a crusher pitman structure which will be light in weight and strong and rigid and durable in service.

Further objects of the invention particularly in the fabrication of the pitman from fiat plate stock will appear from the following description taken in connection with the drawing in which Fig. l is a side elevation with the parts broken away and in'section illustrating a specific construction of this invention,

Fig. 2 is a vertical sectional View of the pitman taken on the line 2-2 of Fig. 1,

Fig. 3 is a horizontal sectional view of the pitman taken on the line 33 of Fig. 1,

Fig. 4 is a perspective View of the pitman de- 20 tached, and

Fig. 5 is a perspective View of the component elements of the pitman detached.

In the crusher shown in Fig. 1, the frame 1 carries a fixed jaw not shown cooperating with the oscillatory jaw 8 mounted on the shaft 9 and oscillated by the toggles Ill, H supported at the rear by the wear shaft pressing against the block l2 carried by the rear head of the machine.

Between the toggles Ill, l l is the replaceable wear shaft l3 engaged on the sides by the socketed ends of the toggles and underneath by the strap portions 2! of pitman l4 mounted above on the upper bearing portion l5 and carrying the lower half iii of the bearing surrounding the ee- 35 centric I! of the drive shaft.

As shown in Fig. 5 the body of the pitman is formed of a heavy metal strip recessed at 24 and 25 and bent at 2i and 22 into generally V shape with the meeting edges welded together as indi- 40 cated at 23. Reinforcing flanges 26 bent from flat strip material into generally U shape as shown are welded to the outside of the pitman structure (Fig. 4), one at each end and one in the middle. These reinforcing strips 2% bridge 45 over the weld 23, adding to the tensional strength of the legs of the pitman and act especially to stiffen the bent plate structure so as to overcome any tendency to pinch too tightly on the bearing portions l5 and Hi.

The interior strut members 2! (Fig. 5) are also welded in place at the ends and center to give additional strength and rigidity. The openings 25 carry the wedge members 28 supporting the lower bearing It.

With this structure the upper larger end of the pitman is of solid construction strongly stiffened against distortion, and also braced by the strut members 21 bridging across between the down- Wardly extending portions of the pitman. Consequently, the weld 23 between the ends of the bent plate forming the pitman body is placed within the structurally strongest part of the pitman. The plate material-used is preferably rolled steel stock very high in tensile strength, and since the structure of the pitman maintains the main stresses in tension the construction is very strong in proportion to its weight. This excess of strength also permits the recesses 24 to divide the lower or toggle end of the pitman into separated straps 2l engaging under the toggle shaft [3 at separated points. These openings 24 receive the bifurcated ends of the toggles ill, I l and permit the end sockets of the toggle to engage against the surface of the toggle shaft l3 between the ends of the pitman. Consequently, the line of effort of the pitman and the line of resistance of the toggle links are in the same vertical plane with no tendency to bend or tip the shaft l3, and the toggles face each other end to end in accurate longitudinal alinement.

The pitman structure of this invention is therefore not only light and sufliciently strong in itself, but also so formed as to most advantageously cooperate with the eccentric drive and toggle mechanism, transmitting the driving stresses directly in line with the toggle effort and maintaining the toggles in proper end to end relation so that the whole mechanism is smooth and balanced in its operation and rugged and durable in service.

I claim:

1. A pitman acting in tension in a crusher or the like and comprising a strap member bent into a closed loop with one end of large diameter and the other end of small diameter and with the ends of the strap joined at the larger end of the loop, reinforcing flange means welded around the periphery of the loop spanning said joined ends of said strap member and extending downward from said periphery on each side and strut means rigidly fastened in place between the interior surfaces of the loop sides in alinement with said flange means and acting to maintain the spacing of said sides during the operation of the pitman, the small end of said loop having openings forming said end into spaced straps alined with said struts and said flange means and adapted for engagement with a central toggle member.

2. A pitman for acting in tension in a crusher or the like, comprising a strap member bent into in substantial alignment from opposite sides thereof through the spaces between said straps, said loop having reinforcing strips extending down to said straps along both its inner and outer surfaces.

GORDON BUCHANAN. 

